Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F01B3/02—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis with wobble-plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B3/00—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F01B3/0002—Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B75/00—Other engines
  • F02B75/26—Engines with cylinder axes coaxial with, or parallel or inclined to, main-shaft axis; Engines with cylinder axes arranged substantially tangentially to a circle centred on main-shaft axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
  • F04B1/2014—Details or component parts
  • F04B1/2078—Swash plates
  • F04B1/2085—Bearings for swash plates or driving axles

Definitions

• the invention pertains to an axial piston machine, in particular an axial piston pump or motor of the type having a first subassembly, including a plurality of circumferentially- spaced cylinder-piston units around a central axis; a second subassembly rotatably connected with the first assembly in a force-transmitting manner with the cylinder piston units in a coupling plane arranged at a predetermined angle to the central axis, wherein one of these subassemblies is rotatably arranged within a housing and coupled with rotational drive means.
• first subassembly is represented by a cylinder-piston arrangement fixed in a housing
• second subassembly is represented by a rotating swash-plate, with the second subassembly, therefore, being a drive subassembly.
• the first subassembly is represented by a rotating drum containing a cylinder-piston arrangement, with this first subassembly thus being a drive subassembly, while the second subassembly is represented by a fixed skew-plate.
• the first subassembly again is represented by a rotating drum, containing a cylinder-piston arrangement, while the second subassembly is represented by a rotating drive plate arranged perpendicular to its axis of rotation.
• the rotational axes of both subassemblies are arranged at an angle relative to each other.
• the second subassembly is the drive subassembly. Substantially no drive torque is transferred to the first subassembly.
• a first objective of the invention is to improve the construction of the axial bearing assembly, which mainly functions to transfer the piston forces that are produced by the hydraulic working pressure of the machine.
• the solution to this problem according to the invention is defined by an axial piston machine, in particular an axial piston pump or axial piston motor, which comprises a first subassembly including a plurality of cylinder-piston units, arranged at a distance from and in parallel to, or at acute angle to a central axis as well as being circumferentially offset, relative to each other around the central axis by a predetermined angle; a second subassembly being rotatably connected with the first subassembly, the second subassembly having a force- transmitting connection with the cylinder-piston units within the range of a coupling plane, being arranged at a predetermined angle to the central axis, so as to receive the oscillating drive forces of the cylinder
• a further objective of the invention refers to the type I. and II. machines. This objective aims at an improvement in supporting or bearing the pistons on a preferably disk-like coupling member, which is rotatably connected with a driving subassembly, in the manner of previously-noted illustration 4- 22.
• the solution to this objective takes the form of an axial piston machine comprising a first subassembly including a plurality of cylinder-piston units arranged at a distance from and in parallel to or under an acute angle to a central axis as well as being circumferentially offset, relative to each other around the central axis by a predetermined angle; a second subassembly having a force-transmitting connection with the cylinder-piston units so as to receive the oscillating drive forces of the cylinder-piston units; these subassemblies being rotatably arranged relative to each other, around the central axis; with one of the subassemblies being rotatably arranged in a housing and functioning as a driving subassembly and being coupled with rotational drive means; wherein a preferably disk-like coupling member is rotatably connected to the second subassembly in relation thereto around a swash axis arranged at a predetermined angle relative to the
• connection thus defined hereinabove between the coupling member and the first subassembly greatly reduces the relative motion in the force-transmitting coupling faces. This produces a desired reduction of friction and wear. It should be clear at this time that such a rotation-blocking coupling connection, in the case of a stationary first subassembly ("swash-plate type") , entails a stationary rotational blocking of the coupling member.
• a further embodiment of the invention provides a cardanic holding device. Due to special advantages, relating to stability and operational safety, the holding device is designed so as to comprise a cardan ring extending along the external perimeter of the coupling member which is connected both therewith and with the first subassembly by means of a pair of diametrical joints.
• the first subassembly is fixedly secured in a housing, while the cardan ring is fixed at the housing by means of a pair of diametrical joints.
• a further embodiment utilizes double-jointed rods, preferably double ball-jointed rods, for the force transmission between the cylinder-piston units and the coupling member.
• Each of the double-jointed rods are connected by means of a first joint to a corresponding piston and by means of a second joint to a corresponding junction apparatus of the coupling member.
• Such a design offers the advantage of minimizing the transverse piston forces without impeding the freedom of the coupling member for necessary minor angular oscillation against the first subassembly around the central axis.
• a further extension of the objective of the invention is directed to improvements of axial piston machines, particularly type I. machines, with regard to a desired structural combination of machine parts that come into contact with the hydraulic working medium, which is often dangerous or corrosive, and with regard to offering easy access to valves, auxiliary units and the like for service and repair.
• an axial piston machine including a plurality of cylinder-piston units which are arranged at a distance from and parallel to or at an acute angle to a central axis as well as being circumferentially offset relative to each other around the central axis by a predetermined angle; a second subassembly being coaxially with and located rotationally around the central axis on a drive shaft, the second subassembly further having a force-transmitting connection with the cylinder- piston units so as to receive the oscillating drive forces of the cylinder-piston units; wherein the drive shaft, which preferably includes at least two rotationally coupled longitudinal sections, extending coaxially with the central axis from its drive input end through a corresponding central opening of the first subassembly or of the housing respectively, to a head-subassembly which includes at least one auxiliary unit coupled with the drive shaft.
• valves, auxiliary units and the like can be positioned in a comparatively freely accessible head- subassembly.
• a special advantage of such a design is that the pistons, located in the first subassembly and connected thereto, are also easy accessible.
• the head-subassembly includes a feed pump coupled with the drive shaft and/or a pump or motor valve assembly.
• a feed pump coupled with the drive shaft and/or a pump or motor valve assembly.
• Fig. 1 is an axial section of a portion of a type I. axial piston pump
• Fig. 2 is an axial section of a further portion of the type I. axial piston pump of Fig. 1, with Figs. 1 and 2 showing two axially adjacent parts of this pump.
• the common radial plane of the two adjacent pump portions is identified by lines 0-0.
• a first subassembly 1 is comprised of a plurality of, for example five, cylinder-piston units 2, which units are arranged at a radial distance from and parallel to a central longitudinal axis 3 as well as being circumferentially offset, relative to each other around the central axis by an appropriate angle, for example 72°.
• Each cylinder-piston unit is comprised of a piston 4 slidably arranged in a cylinder 5 with piston 4 and cylinder 5 being shown in axial sections only over a part of their axial length. Specific design details of cylinder 5 and piston 4 are only of minimal interest in the present context, since cylinder-piston units 2 may be of any type well known in the art.
• a pretensioned return coil or compression spring 6 surrounds cylinder 5 and acts through a sleeve 7 against a radially projecting bottom flange 8 of piston 4, thus tending to push piston 4 in its restoring or cylinder-filling direction (in the Figures from the left to the right) .
• the inner (in Fig. 2 the left) end of spring 6 abuts on the right end face of a support sleeve 9 fixedly retained in an axial bore of a machine housing 10.
• Support sleeve 9, on its right side, is fixedly secured to the left end portion of cylinder 5.
• housing 10 is tightly connected, e.g. by means of highly pretensioned axial screws 11, with a head-subassembly 12, which among other parts houses a valve assembly 13 and a filler or feed pump 14 attached to a section 15 of a drive shaft 16 (Fig.l).
• Drive shaft section 15 is coupled, by means of -a toothed-clutch 17, to a central drive shaft section 18.
• Filler pump 14 serves to enhance the input hydraulic pressure for the cylinder-piston units 2 to a value sufficient for avoiding cavitation.
• Drive shaft section 18 also drives a lubricant pump 19, which in turn feeds a lubricant channel system 20 via a lubricant filter 21.
• each cylinder-piston unit 2 Coaxially attached to each cylinder-piston unit 2 is a combined inlet-outlet valve 22 having an inlet side 23 connected, via in inlet channel system 24, to the output 25 of filler pump 14.
• Pump 14 e.g. is of the well-known "side- channel” type and will not be described in detail here since it is not material for the essence or function of the invention.
• Filler pump 14 is connected, via an input 26, to a non-illustrated external low-pressure hydraulic feed system.
• Inlet/outlet valve 22 further has an output side 27, connected through an output channel system 28, to a non-illustrated external high-pressure hydraulic system.
• Valve 22 has substantially coaxial internal flow channel systems and spring-loaded check valve members for both flow directions, i.e.
• valve 22 is of no specific interest for the invention and thus will not be described in further detail. In principle, instead of the noted example of the combined inlet/outlet valve 22 described here, other conventional and well-known valve types may be used.
• a second subassembly 29 is rotatably arranged relative to first subassembly 1.
• Subassembly 29 is in force- transmitting connection with cylinder-piston units 2 within the range of a coupling plane 30, arranged at least approximately right-angled or perpendicular to the central longitudinal axis 3, so as to absorb the oscillating drive forces produced by cylinder-piston units 2.
• Subassembly 29 is constructed as a driving subassembly that is rotatably arranged in housing 10 and coupled with a main section 31 of drive shaft 16.
• Drive shaft sections 18 and 31 are coupled by means of any type of a conventional clutch.
• cylinder-piston subassembly 2 may be designed as a rotating drum, i.e. in the sense of previously-noted machine types II. and III. In the latter case, this subassembly would be a substantially torqueless rotating unit.
• Driving subassembly 29 includes a bearing assembly comprising two first bearings 33, 34, which act at least substantially in the radial direction and are arranged at a predetermined axial distance or spacing from each other, and a swivel-joint or pivot-type second bearing 35 acting both axially and radially.
• bearings 33 and 34 may take the form of axially movably cylindrical roller bearings, while bearing 35 may be a mainly axially acting spherical roller bearing.
• the swivel or pivot center 36 of second bearing 35 is located at about the axial mid-point (center-to-center distance) 37 between the mid-points 38, of the bearing axial width 39, of axially spaced first bearings 33, 34.
• Subassemblies 1 and 29 are arranged so as to be rotatable, in relation to each other, around their common central axis 3. Only one of these subassemblies, here subassembly 29, is arranged to be rotatable in housing 10 and functions as a driving subassembly, coupled with the drive shaft 16. However, as already noted earlier, a design according to machine type III. may also be utilized.
• a disk-like coupling member 40 is rotatably connected to second subassembly 29 around a swash axis 41, which is arranged at an angle relative to the central axis 3.
• Coupling member 40 is ' further connected to first subassembly l in a manner so as to be blocked against continuous rotation around central axis 3, and is connected in a force- transmitting manner with the cylinder-piston units 2 within the range of coupling plane 30.
• Coupling plane 30 is arranged at least approximately right-angled or perpendicularly to swash axis 41.
• coupling member 40 takes over or absorbs the substantially axial, oscillating drive forces produced by cylinder-piston units 2 and transmits such forces to second subassembly 29. It should be understood that coupling member 40 can also be regarded as a part of second subassembly 29.
• the noted rotation-blocking connection between coupling member 40 and first subassembly 1 is accomplished by means of a positively-acting holding device 42.
• holding device 42 is a cardan type of device
• cardan ring 43 which extends along the external perimeter of coupling member 40 and which is connected with each of coupling members 40 and subassembly 1 by means of a pair of diametrical pivots 44.
• cardan ring 43 is fixed to housing 10 by means of a further pair of non- illustrated diametrical pivots.
• double-jointed rods 45 preferably double ball- jointed rods, are provided for the force transmission between cylinder-piston units 2 and coupling member 40.
• drive shaft 16 is comprised of three rotationally coupled sections 31, 18 and 15.
• Drive shaft 16 extends coaxially with central axis 3 from its drive input end 49 through a corresponding central opening of first subassembly 1 and of housing 10 to head-subassembly 12 with feed pump 14 and valve assembly 13.
• valve assembly then must be positively coupled to and synchronized with the rotation of the drive shaft, which then functions as a power output shaft.
• the filler pump can be omitted or replaced by other useful auxiliary units.
• the angle between the swash axis and the central axis may be predetermined so as to be of a fixed acute angle value or so as to be variably adjustable in operation between 0° and a maximum acute angle value, and this with angle variation to both sides of the zero angle value if desired for purposes of hydraulic flow direction reversal.
• Such variation obviously entails a corresponding variation of the angle between the coupling plane and the central axis, which is the complementary angle to the one between the swash axis and the central axis and determinative for the magnitude of the piston stroke.
• This type of of swash plate axial piston machines with variable swash-angle is well known in the art per se.
• the realization of the subject of the present invention for such variable-swash- angle machines can be established by usual structures near at hand and needs no further explanation.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Reciprocating Pumps (AREA)
• Details Of Reciprocating Pumps (AREA)

Applications Claiming Priority (4)

Publications (2)

Family

ID=4236691

Family Applications (1)

Country Status (10)

Families Citing this family (5)

Family Cites Families (13)

• 1993
  • 1993-08-04 ZA ZA935640A patent/ZA935640B/xx unknown
  • 1993-08-05 CN CN93109269A patent/CN1057584C/zh not_active Expired - Fee Related
  • 1993-08-06 EP EP93917765A patent/EP0705380B1/de not_active Expired - Lifetime
  • 1993-08-06 AU AU47083/93A patent/AU689076B2/en not_active Ceased
  • 1993-08-06 AT AT93917765T patent/ATE192214T1/de not_active IP Right Cessation
  • 1993-08-06 WO PCT/EP1993/002106 patent/WO1994003708A1/en not_active Ceased
  • 1993-08-06 CA CA002141812A patent/CA2141812A1/en not_active Abandoned
  • 1993-08-06 KR KR1019950700427A patent/KR100316356B1/ko not_active Expired - Fee Related
  • 1993-08-06 DE DE69328499T patent/DE69328499T2/de not_active Expired - Fee Related
  • 1993-08-06 JP JP6505028A patent/JPH08502797A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events